If you are up to a 2 wheel ride down the I-15 fwy, hook a left at Bundy Canyon, about 20 miles south of the I-91 and stop by my place. We can talk woodies while sharing a cup of coffee, which is always on. I think I can give you a few tips on fabricating and installing your wooden trim without having to steam-bend a single piece. It worked for me, and you might decide to do the same.
I have built 2 tears on HF frames, and have over 15,000 miles on 12 inch wheels and tires with no problems. Extending over the front or the rear of the frame was no problem on either of my teardrops. By the way, I see you plan on having wooden vertical members extending from the very bottom to the top of the side of your rig. That is where you can join the 2 sheets of plywood, right behind one of them and back it up with a matching piece on the inside. Probably better (and easier) than scarfing or splicing. Come on by, lets talk. Pop me a pm and lets make it happen.
Roly, the ol' retired woody TD designer, builder, "varnisher" and user!
to the playground 
hummm whats I'm gonna call you. GED doesn't really work now does it. 
Course I have been known to miss a name and I am late to the party.
